Image Resize

About this tool

What happens to animated GIFs?

They get flattened to a single static frame. Resizing goes through <canvas>, which has no concept of animation — if you need to preserve an animated GIF, this isn't the right tool for it.

Why does "Don't enlarge smaller images" exist?

Upscaling a raster image beyond its native resolution just blurs or pixelates it — there's no extra detail to recover. This guards against accidentally blowing up an image when a batch contains some images smaller than the requested target; that image is left at its original size instead.

What does "Keep original format" do?

Each image is re-encoded to the same file type it started as, so a JPEG stays a JPEG and a PNG stays a PNG. Choosing an explicit format (PNG/JPEG/WebP) instead converts every image in the batch to that type regardless of the original — handy for batch-converting a folder to WebP, for example.

Why does "Download all" produce a .zip instead of several files?

Browsers block or prompt on automatic multi-file downloads triggered without a click per file, so downloading a batch one-by-one is unreliable. Bundling everything into a single .zip — built entirely in your browser, no server or library involved — sidesteps that limitation and gives you one clean download.

Does this tool upload my images anywhere?

No. Every image is loaded, resized, and re-encoded entirely in your browser using the Canvas API. Nothing is uploaded to a server.

Configuration options

Resize by

Width or Height scales the image to that one side, computing the other automatically to preserve the aspect ratio. Percentage scales both sides by the same factor. Exact width × height sets both sides directly and does not preserve aspect ratio — the image will distort if the ratio differs from the original.

Don't enlarge smaller images

Skips upscaling: if the requested size is bigger than an image's original size, that image is left at its original dimensions instead. Ignored in Exact mode, since that's an explicit override.

Output format

Keep original re-encodes each image to its own source type. PNG/JPEG/WebP converts every image in the batch to that one format.

Quality

Only shown for JPEG and WebP, since both are lossy formats with an adjustable compression level — PNG is always lossless, so there is nothing to trade off. Lower values produce smaller files at the cost of visible compression artifacts.